The increasing prevalence and sophistication of wireless sensors is creating an opportunity for improving, or in many cases enabling, the real-time monitoring and control of distributed physical systems. However, whilst a major issue in the use of these sensors is their resource utilisation, there has only been limited consideration given to the interplay between the data sampling requirements of the control and monitoring systems and the design characteristics of the wireless sensors. In this paper we describe an approach to the optimization of the resources utilized by these devices based on the use of synchronized state predictors. By embedding state predictors into the sensors themselves it becomes possible for the sensors to predict their optimal sampling rate consistent with maintaining monitoring or control performance, and hence minimize the utilization of limited sensor resources such as power and bandwidth.

As the result of recent advent and rapid growth of the Internet, there have been an increasing number of corporations relying on computers and networks for communications and critical business transactions. Because of the network complexity and advanced hacking techniques, such reliance on computer networks often presents unanticipated risks and vulnerabilities. A huge volume of attacks on major sites and networks have been recently reported including those of private companies, government agencies and even military classified networks. Therefore, it is important to deploy protection measures for networks and their services from unauthorized modification, destruction, or disclosure of sensitive information. Intrusion detection systems (IDS) have emerged as an important part of todays network security infrastructure which can monitor the network traffic and detect possible attacks. Currently existing IDS suffer from low detection accuracy and system robustness for new and rare security breaches.

This paper presented an economic model for productivity of software corrective maintenance. The productivity is modeled using economic value of the maintenance process as the output, and the pre-committed fixed cost and variable cost as input. The relationship of the economic value and these cost components are modeled using analytical theory of investment. The values of corrective maintenance process are analyzed. A simulation approach is demonstrated to analyze the influences to the productivity in corrective maintenance. This approach provided a tool to identify and analyze the optimal parameters in productivity using the economic model and simulation.

The mainstream approach to software development productivity has been on identifying factors of impacting on software development productivity and the static relations between the impact factors and performance. This paper presents a dynamic relationship based on economic theory. The findings provide practitioners with insight into how these factors interact and impact on project productivity. Through simulation based on the Analytical Theory of Project Investment, we have demonstrated the dynamic relationship between project duration, the uncertainty level of the perceived project value and the fixed project upfront cost.

Zero velocity update (ZUPT) is an effective way to correct low cost inertial measurement unit (IMU) errors when it is foot-mounted for pedestrian navigation. The stance phase in steps provides zero velocity measurement for inertial sensor error correction. As the errors of IMU estimated position and velocity grow rapidly with time between each correction, ZUPT applied at each step leads to sharp corrections and discontinuities in the estimated trajectory. For motion analysis and visualization, these large corrections are undesirable. Consequently, the implementation of smoothing for ZUPT-aided INS is considered to eliminate the sharp corrections. In this paper, we propose a closed loop Rauch-Tung-Striebel (RTS) smoother using a 24 error states extended Kalman filter (EKF) implement on our previous pedestrian navigation systems. Unlike common RTS smoother which operates as off-line processing mode, a near-real-time stepwise smoother is implemented to eliminate the sharp corrections over the steps. The impact of the near real-time smoothing filter for different step manners (walk, run and climb stairs) combined with the Constant Velocity Update (CUPT) concept we proposed previously is illustrated and analysed. Experimental results show that the proposed method can dramatically improve pedestrian navigation smoothness.

Wireless sensor networks (WSN) are extensively applied in civil and military areas. Localization is an essential prerequisite for many WSN applications, and is often based on beacons that provide geographical information in real time. Mobile Beacons (MB) can be used to replace many static beacons with paths that can be controlled in real-time. Robotic and/or flight vehicles can work as MBs. In this paper we consider the use of reinforcement learning (RL) (a significant branch of machine learning) to control MBs. Usually, RL needs an infinite series of episodes to determine an optimal policy. We propose however a method of localization employing mobile beacon whose behavior will be controlled by an adapted RL algorithm. A MB learns and makes decisions based on weighted information collected from unknown sensors. Simulation results show that the adapted RL algorithm provides sufficient information to the MB to localise unknown sensors in a lightweight but effective way

Information infrastructure for healthcare is undergoing a transformational shift in the way it is perceived and used by health professionals. This is driven by the need to unify patient records seamlessly, and integrate emerging technologies in the Sensor-Actor Network (SANET) realm that incorporate patient sensory systems such as wireless sensor networks and body-area networks. By harnessing The Open Group Architecture Framework (TOGAF), it ensures integrity is considered throughout development processes by analyzing the problem space and scenarios, constraints, requirements, risks, enablers and inhibitors of the legacy application architectures. The proposed architecture with TOGAF components incorporating SANETs addresses the need to harmonize legacy operations in a consistent manner with industry best practice to ensure universal patient records are comprehensive and secure, thus protecting against identity theft and adhering to privacy regulation compliance.

Sensor data with geographical information become ubiquitous with development of location base applications in various businesses. There is no exception to Wireless sensor network (WSN) as it is getting more practical under the booming of semiconductor industry. Localization of WSN usually depends on beacons that equip with GPS or GSM module. The cost of finance and energy hamper the application of WSN. Robot or flight vehicle called Mobile Beacon (MB) can relieve the issue and enhance the application area of WSN. Based on the framework we proposed in [14], we renovate the algorithm to find the best position for MB in every step by grouping weight of cosine similarity to mining the relation between responsible sensors. The MB machine works in an autonomous mode to find dynamic path without any supervision. In simulation, it is proved that the novel method makes the best of observation and covers unknown sensors as many as possible without heavy computation and struggle of energy. With appropriate parameters, the method can reach a 90% average coverage rate on any random distribution of sensors.

Localization is one of the basic prerequisites of sensors in various applications of wireless sensor networks. A beacon is a special sensor with geographical knowledge and which can be employed to help localize general sensors. A mobile beacon is treated as a replacement for many static beacons since it is movable and flexible and often powerful. The path of a mobile beacon will determine the rate of coverage and accuracy of position determination that it supports. Whereas a static path is planned before any localization action, a dynamic path is determined in real-time based on the demands of initially unknown sensors and hence can be more efficient than a static path. In this paper, we proposed a method of localization employed a mobile beacon whose path will be selected according to the real-time information of unknown sensors. The method is designed to be both thrifty in both energy consumption and economical cost, and lightweight in terms of computation load. Simulation results show that the method is lightweight but effective and efficient.

A new modeling approach to analyze the impact of schedule pressure on the economic effectiveness of agile maintenance process is presented in this paper. Based on a causal loop diagram the authors developed earlier and the analytical theory of project investment, this paper analyzed the effect of schedule pressure on the economic effectiveness. Preliminary results show that maintenance effectiveness is low when schedule pressure is high, and is high when schedule pressure is low.

Global Navigation Satellite Systems (GNSS) provide positioning service to civil applications. At the end user's side, these positioning services will have different position accuracy levels when satellite signal configurations and receiver noise levels are different. In this paper, a position error modeling is presented using a black-box approach. Using this approach, end users will treat the entire signal biases and receiver noises as a black-box transfer function. No efforts are made to model many different individual error sources of satellite signals and receivers. Further, a different type of sensor is chosen to aid the error de-correlation. Experimental results in different configurations are presented.

A major trend in the evolution of the Web is the rapidly growing numbers of web-enabled sensors which provide a rich ability to monitor and control our physical environment. The devices are often cheap, lightweight, rapidly deployed and densely interconnected. The current dominant models of Web-based data monitoring are not well-adapted to the operational needs of these devices, particularly in terms of resource utilization. In this paper we describe an approach to the optimization of the resources utilized by these devices based on the use of synchronized state-observers. By embedding state observers with a minimized footprint into both the sensors and the monitoring Web client, we show that it is possible to minimize the utilization of limited sensor resources such as power and bandwidth, and hence to improve the performance and potential applications of these devices.

Although DGPS provides positioning information with high precision, when DGPS is unavailable in some situations, stand-alone GPS has to be used in vehicle navigation. The accuracy of standard GPS is low due to position measurement errors. This paper presents a frequency domain modeling approach to model GPS errors and increase GPS positioning accuracy. This approach models GPS errors using shaping filter. External sensors are employed to reduce GPS errors. This paper also presents an approach to select external sensors to meet the quality requirements of positioning system.

Existing design methods used for developing webcentric systems are mostly adapted from methods for designing traditional software systems. Web-centric systems however differ from traditional software systems, in terms of both organizational and technical characteristics. Effective design methods for webcentric systems need to address these characteristics specific to web-centric systems. This paper proposes a design method for web-centric systems. The de-sign process comprises three steps: prototyping, information modeling and sys-tem architecture design. The method is differentiated from existing design methods in that the design process commences from user interface prototyping. Information modeling activities are further enhanced in this method. To cope with the complexity of web systems, each design step is partitioned into both structural modeling and behavioral modeling. The design method is illustrated by applying the method to the design of a commercial web application.

Web applications have rapidly become critical to the interaction that organisations have with their external stakeholders. A major factor in the effectiveness of this interaction is the ease with which users can locate information and functionality which they are seeking. Effective design is however complicated by the multiple purposes and users which Web applications typically support. In our earlier work we described a model for evaluating the overall navigation entropy of a Web application which provides a measure of the weighted effort required of users. In this paper we describe a navigational design method aimed at minimizing this navigational entropy. The approach uses a theoretical navigational depth for the various information and service components to moderate a nested hierarchical clustering of the content.

Web applications have rapidly become critical to the interaction that organisations have with their external stakeholders. A major factor in the effectiveness of this interaction is the ease with which users can locate information and functionality which they are seeking. Effective design is complicated by the multiple purposes and users which Web applications support. In our earlier work we described a model for evaluating the weighted effort required of users. In this paper we describe an approach to minimizing this navigational effort.

Web applications have rapidly become critical to the interaction that organisations have with their external stakeholders. A major factor in the effectiveness of this interaction is the ease with which navigation within the application can occur, and especially the extent to which users can locate information and functionality which they are seeking. Effective design is however complicated by the multiple purposes and users which Web applications typically support. Despite the fact that this implies that navigation design is inherently an optimisation problem, few optimisation techniques have been applied in this domain - with most design techniques being based on intuition, general heuristics, or experimental refinement. In this paper we discuss this problem, and propose a navigation representation which can become the basis for optimisation techniques.

Identifying impact factors on software development productivity and the static relations between the impact factors and performance has been the main focus in the literature. Insight into the dynamic relation between key factors and performance dimensions would expand and complement the conventional wisdom on software development productivity. This is the first study to present such dynamic relationship based on an Analytical Theory of Project Investment. Through simulation, we have demonstrated the dynamic relationship between project duration, the uncertainty level of the perceived project value, the fixed project upfront cost and software development productivity. The findings provide practitioners with insight into how these factors interact and impact on software development project productivity.

In the paper, principles of signal and information were introduced to the design of GNSS receiver. Analyze Antenna and radio frequency (RF) front-end with the perspective of transmission link, Understand the baseband processing though signal modulate and demodulate, design the navigation calculation utilized the information pick-up and disposal, and research the receiver system by the inherent connection between signal and information. New ways and means would be developed though these researches. (2013) Trans Tech Publications, Switzerland.

Considering that the GPS carrier tracking loop is fragile in high dynamic and weak signal environments, carrier tracking loop with information aided from inertial sensors is designed in this paper. The conflicts between loop noise and dynamic stress are analyzed, which are existed in the bandwidth design of carrier tracking loop. To address this problem, the information of inertial sensors is brought to the carrier loop design, which takes advantage of the relation between relative motion and Doppler frequency shift. Simulation results indicate the inertial sensors aided tracking loop could improve the performance of anti-interference and anti-dynamic significantly. Copyright 2013 American Scientific Publishers.

This paper presentsa new simple mobile tracking system based on IEEE802.11 wireless signal detection, which can be used for analyzingthe movement of pedestrian traffic. Wi-Fi packets emitted by Wi-Fi enabled smartphones are received at a monitoring station and these packets contain date, time, MAC address, and other information. The packets are received at a number of stations, distributed throughout the monitoring zone, which can measure the received signal strength. Based on the location of stations and data collected at the stations, the movement of pedestrian traffic can be analyzed. This information can be used to improve the services, such as better bus schedule time and better pavement design. In addition, this paper presents a signal strength based localization method.

This paper presents a system design approach for vehicle positioning systems. Global Navigation Satellite Systems (GNSS) and inertial sensors are major positioning measurements used in this approach. A number of phases are designed in this approach including: system architecture design using an estimator, GNSS error modeling, estimator low level design, simulation and experiment design, frequency domain simulation, time domain experiment, sensor selection and deployment decision making. This approach enables to model GNSS errors from end user's view point, and choose low cost inertial sensors to meet positioning system requirements using a new sensor selection criterion.

Although Differential Global Positioning System (DGPS) provides positioning information with high precision, when DGPS is unavailable in some situations, stand-alone GPS has to be used in vehicle navigation. The accuracy of standard GPS is low due to position measurement errors. This paper presents a frequency domain modelling approach to model GPS errors and increase GPS positioning accuracy. This approach models GPS errors using shaping filter. External sensors are employed to reduce GPS errors. This paper also presents an approach to select external sensors to meet the accuracy requirements of positioning system.

Traceability analysis is crucial to the development of web-centric systems, particularly those with frequent system changes, fine-grained evolution and maintenance, and high level of requirements uncertainty. A trace model at the level of the web system architecture is presented in this paper to address the specific challenges of developing web-centric systems. The trace model separates the concerns of different stakeholders in the web development life cycle into viewpoints; and classifies each viewpoint into structure and behaviour. Tracing relationships are presented along two dimensions: within viewpoints; and among viewpoints. Examples of tracing relationships are presented using UML. This trace model is demonstrated through its application to the design of a commercial web project using a web-design process. The design artifacts in each activity are transformed based on the artifacts tracing relationship in the trace model. The model provides mechanisms for verification of consistency, completeness and coverage within each viewpoint and the connectedness across viewpoints.

Architecture frameworks have been extensively developed and described within the literature. These frameworks typically support and guide organisations during system planning, design, building, deployment and maintenance. Their main pupose is to provide clarity to the different modelling perspectives, abstractions, and domains of consideration within system development. In dpoing so they allow improved clarity with regard to the connections between the different models, and the selection of models tht are most likely to capture salient features of the system. In this paper we present an Architectural Framework which takes into account the specific characteristics of web systems. The framework is based around a two dimensional matrix. One dimension separates the concerns of different participants of the web system into perspectives. The second dimension classifies each perspective into development abstractions: structure (what), behaviour (how), location (where) and pattern. The framework is illustrated through examples from the development of a commercial web application.